Valve means for pressure cookers



SePt- 1 1942 E. G. GRuNDs'rRoM 2,294,746

VALVE MEANS FOR PRESSUREY COOKERS Filed March s, 1939 2 sheets-sheet 1@1' @num l@ i Inn -Y Irda G @rmi/*077g l@ www Sept 1, 1942- E. G.GRuNDs'rRoM 2,294,746

I VALVE-MEANS FOR PRESSURE COKERS y Filed March 8. 1939 `f2 Sheets-Sheet 2 lll/l Patented Sept. l, 1942 UNITED STATES PATENT OFFICE2,294,146 v VALVE MEANS FOR PRESSURE COOKERS Erik G. Grundstrom,Chicago, lll., assignor to Advance Aluminum Castings Corp.,

Chicago,

in valve means for pressure cookers.`

This application is a continuation ln part of application Serial No.118,881, filed January 2, 1937by the present applicant.

A The description of the present invention may s be prefaced by thestatement that in pressure cookers avesselcontaining the material to becooked is tightly sealed and heated to a suiliciently high temperatureto cause the generation of steam either from the moisture of thematerial being cookedor from other liquid contained within said vessel.After a predetermined pressure has been attained, the vessel may beremoved from the source of heat and the'material therein subjected totemperature and pressure conditions for a predetermined length of time.

An object is to provide a valve for a pressure cooker which may bereadily assembled and disassembled for convenience of cleaning. packingand shipping.

A further object is to provide an improved valve for a pressure cooker,which valve has associated therewith a warning -whistle and a protectiveby-pass for said whistle.

A further obect is to provide al warning signal which will operateefliciently throughout' the entlre range of pressures for which thepressure cooker is designed to operate.

Further objects will appear as the description proceeds.

Referring to the drawings-- Figure 1 is a view in side elevation of oneembodiment of the present invention;

Figure 2 is a top plan view of the structure shown in Figure 1; l

Figure 3 is a sectional view on an enlarged scale taken along the planeindicated bythe ar.;- rows 3-3 of Figure 1;

Figure 4 is a sectional view on an enlarged scale taken along the planeindicated by the arrows 4-4 of Figure 2;

Figure 5 is a sectional view taken along the plane indicated by thearrows 5-5 of Figure 4;

Figure 6 is a sectional view taken along the plane indicated by thearrows 6 6 of Figure 4; and

' Figure 7 is a fragmentary view on an enlarged scale illustrating animproved sealing means for the cover of the cooker.

The numeral I indicates a vessel. Said vessel Il is provided with theelliptical opening I2 tuberance I8, preferably said flange I4 and saidVilange I3. As shown in Figure 2,` the cover II is provided with aprolocated at one extremity of the long axis of said cover, adapted to tinto a corresponding recess in the adjacent portion of the vessel I0.Said cover II at the other extremity of its long axis is provided with aprotuberance Il tting into a corresponding recess in the vessel III.Saidprotuberances I6 and II arepreferably of diii'erent sizes, so thatthe operator of the pressure cooker will be guided by said protuberancesin placing the cover II in proper position relative to the vessel '|0.The gasket I5 is recessed to correspond to the protuberances I6 and I1.'I'he :flange I4 on its upper surface is provided with a bead I'laextending around the cover, which bead is adapted to embed itself intothe gasket I5 when pressure is exerted between the anges I3 and Il, aswill be explained presently, thereby greatly improving the sealingaction of the gasket I5. A further advantage of the bead I 'Ia is that,since the gasket I5 will in service receive a more or less permanentindentation from the bead I'Ia, said bead and said indentation willconstitute indicating means to insure the same setting of the gasket? I5with reference to the ange I4 at all times. Particularly in cooperationwith the protuberances I6 and I'I, the flanges I3 and I4 and the gasketIii-will always have the same setting relative to one another, therebyavoidi .g the faults of some gaskets that after they lose theiroriginal-resiliencethey lose their elciency due to the fact that it isnot possible to always reset them in correct relationship with referenceto the ymembers between which they are to perform their sealingfunctions.

Mounted centrally of the cover II is the upstandlng threaded stud I8having a. handle I9 fixed to its upper extremity. Said handle I9 ispreferably of heat insulating material, whereby the cover Il and thevessel I0 may be readily manipulated. Underlying said handle I9 is thespring 20 rotatable about the studv I8 and having two extremitiesadapted to bear against the upper surface of the flange I3 o f thevessel III.

Said extremities of said spring 20 are adapted to abut against abutments2I-'2I formed integral with said flange I3 of the vessel I 0,. The uppersurface of the flange I3 adjacent to the abutbounded by the ilange I3.The cover II is provided with a ange I4 adapted to underlie the hflangeI3, the gasket .I5 being provided between 55 ments 2I-2I may be slightlyraised, as indicated by the numeralsy 22-22, whereby as the spring `2liis turned away from its operative position as shown in Figure 1, saidspring20 will be' quickly ing of the surface of the flange I3. l'

released without binding or unnecessary ',scratchv The stud I8, whichcarries the handle I9, is screwthreaded within the cover -I I, and aspring 23 is provided between the upper side of the cover II and theunder side of the spring 20 for holding the extremities of the spring 20away from the cover II when said cover is removed from the vessel I8.The spring 23, by holding the member 20 against`the lower extremity ofthehandle I9, facilitates the handling of the entire cover assembly, asthe distance between the cover and the lower extremity of the handle I9will vary considerably. The

handle I8 and its stud I8 are threaded into the,

nut 24, which nut is externally threaded within the boss 25 extendingdownwardly from the under side of the cover II. The upper surface oi'the head 24a of the nut 24 is provided with the circular head 24hadapted to embed itself into the gasket 24e.

The numeral 26 indicates as a whole a fuse plug carried by the coverIiI. includes the fusible element 21 mounted within Said fuse plug f.

the plug member 28, which plug member 28 is externally screw-threadedand is adapted to be mounted within a correspondingly `tapped hole inthe cover II. The plug member 26 is provided with the head 29a; by meansof which the fuse plug 26 may be screwed tightly into position. Thetapped hole in the cover is tapped only at its lower end, and the plugmember 28 is threaded only adjacent to the head 29a, and accordingly itis impossible to screw in the fuse plug 26 from the wrong direction. Agasket 30 is provided between the head 29a and the cover II forproviding a tight joint. The upper surface of the head 29a will beprovided with an which forms the present invention. Under normaloperation the vessel I0 with its cover II form a tightly sealedenclosure, steam generated therein being prevented from escape exceptthrough said valve 35.

The valve in the illustrated embodiment of the present inventionincludes the stem 36 having the reduced threaded end portion 31. Saidthreaded end portion 31 is adapted to project through an opening A38 inthe cover II. Said valve stem 36 including its reduced end portion 31has tight sealing engagement with the cover II, whereby no iiuid mayescape therebetween. Preferably said stem 36 will be so tightly securedto the cover II that it will not be removable by the user, so that nodifllculties will be encountered in service by leakage around `saidstem. The stem 36 is provided with the axial bore 39, the lowerextremity of which is reduced in diameter to provide a valve seat 40.The upper portion of the stem 36 is internally screwthreaded for thereception of the nut '4I provided with the depending skirt 42, which nut 4I and skirt 42 provide an elongated bearing for the longitudinallyreciprocable valve member 43.

. Said valve member`43 is adapted to seat by annular bead 29h, whichwill become embedded in the gasket 38 to provide a tight seal withoutrequiring excessive tightening eort on said plug 26. As clearly shown inFigure 3, the fusible element 21 is tapered, the larger extremitythereof being uppermost. By reason of this construction, in the eventthat an excessive temperature is developed in the cooker, the fusibleelement 21 will first soften and be released from the plug member 28,permitting the escape of steam from within the vessel I0. By reason ofthis construction the melting of the fusible element 21 is avoided. v

The numeral 3| indicates a shield covering the upper'extremity of thehole in which the plug 26 is mounted. Said shield is releasably held inposition by means. of the spring 23 and is releasably held relative tosaid-hole by a pair of struck out portions 32-32 adapted to seat withincorresponding recesses in the upper side of the cover II. By reason ofthe shield 3|, in the event that the fusible element 21 is released,juices and other fluid materials within the vessel I Il will beprevented from spurting over the region adjacent to the vessel I0, butwill be deflected and merely flow downwardly on the cover il .and alongthe sides of the vessel As shown in Figures 1 and 2, the vessel I0 maybe provided with a pair of handles 33--33, which maybe of heatinsulating material, each of said handles being supported by a pair oflugs 34-34 integral with the vessel I0. At the two ends of each of thehandles 33-33 on the inner sides .of the lugs 34-34 are the guard disks34a-34a of heat insulating vvmaterial, which protect the hands of theoperator from contact with the hot metal lugs 34'34.

The numeral 35 indicates asa whole a valve, 75 weight 54 from said leg48a. Said leg 48a 1S4 gravity in the'valve seat 40, thereby controlling/communication between the interior of the vessel I0 and the outsideatmosphere. The lower extremity of the bore 38 may be protected by thescreen 44, which screen is mounted within the nut 45 adapted to havescrew-threaded engagement with the lower extremity 31 of the valve lstem 36.

The present invention contemplates a novel method of forming the valveseat for the valve member 43. Said valve member will be provided withan'end surface which is as nearto a true cone as is practicable tomanufacture. Said valve member will preferably be made of hard material,such as MoneIl metal. The seat 40 of the stem 36 will be made o1 brassand is accordingly relatively soft. The valve seat' for the valve member43 is formed by tapping the end of valve member 43 while it is beingrotated so that a truly conical seat is provided.

The upper extremity of the valve member 43 is provided with the head 46adapted to cooper- 'ate with the lever arm 41. Said lever arm 41 in theillustrated embodiment of the present invention comprises a J-,shapedmember, including the legs 48 and 48a, the leg 48 of which has abifurcated end. One of the bifurcations, indicated by the numeral 49,seats under the head 46 of the valve member 43. The other of saidbifurcations,

,indicated by the numeral 50, is adapted to be engaged by the valvemember. 43 when said valve nember is raised by steam pressure withinythe cooker Said bifurcation 50 is also adapted to engage under a struck`out portion 5I of aleaf spring 52 secured to said valve stem 36. Saidlever 41 is swingingly mounted upon the valve stem 36 by means o f thepin 53. Said pin 53 is provided with the knurled bead 53a and anadjacent threaded portion 53h threaded into the adjacent part of thestem 36. The distant extremity of the pin 53 acts merely asa pilot pin.By reason of this construction, if the pin 53' should be broken, nodifliculties will be encountered in replacing said pin. The leg 48a ofthe lever is4 threaded for the reception of a weight 54, which isprovided with a threaded hole. The outer extremity of the leg 48a isprovided with the cross pin 55 for preventing the escape of the actingas markers for positioning the weight 54.

Mounted upon the valve stem 35 and having communication with the axialbore 39 thereof is the'assembly 55,A which includes a warning whistleand also a relief valve. Said assembly includes the externallyscrew-threaded stem 55 threaded into the valve stem 36, which Istem 55Said assembly 55 well known in the art. Said whistle 53 provides a pathfor communication between the interior of the vessel and the outsideatmosphere. The numeral 64 indicates a thermometer for indicating thetemperature within the cooker. This thermometer will be marked withindicia along its length to correspond with the indicia` disposed alongthe length of the leg 48a. By reason of the relationship betweentemperature and pressure, there can be a direct relationship between theindicia on said leg 48a and on the thermometer 64.

The mode of operation of the above described embodiment of the presentinvention is substantially as follows: The operator of the cookerwillplace the materials to be cooked within the vessel Ill and will theninsert the coverll, tting the protuberances I and I1 within theircorresponding recesses and turning the handle I9, thereby swinging theextremities of the spring 20 above the raised surfaces 22--22 until saidextremities abut against the abutments 2I-2I. The oper- 2,294,748provided with indicia disposed along its length I ator will continue toturn the handle I9 to bring"` the ange I4 of the cover II with itsgasket I5 into close engagement with the under side of the flange I3ofthe vessel I0. By reason of the protuberances I6 and I1, the turningofthe handle I9 will not cause the jamming 'of the cover II into thematerial of the vessel I0, An easy fit may be provided for said coverII. within the weight 54 as to cause the valve member 43 to lift when apredetermined pressure is reached within the cooker.

As the temperature rises Within the cooker,

steam 'will be generated within the vessel I 0 until` the pressurethereof is suilicient to force upwardly the valve member 43. Upon theattainment of such pressure, the head 4B of said valve \member 43 willengage the under side of the bifurcation 5U of the lever 41, swingingsaid lever about the axis of thel pin 53. Under these circumstancessteam will escape past the valve member 43 into the assembly 55. Part ofsaid been sounded by the whistle 53, will turn the weight 54 out to theextremity of the leg 48a of vthe lever 41, whereby the effect of saidweight 54 will be a maximum. The operator at this time will remove thecooker from the source of heat. Under these conditions the pressurewithin the cooker will be maintained for a prolonged period of time.After the cookerhas been removed from the source of heat and thematerial therein has been subjected to the existingl temperature andpressure conditions within the cooker'for a predetermined period oftime, which period can be readily determined by simple experimentationwith diierent materials being cooked, the operator will tilt the leg48a, thereby raising the bifurcation 50 above the struck out portion 5Iof the spring 52. This action will result in lifting the valve member'43 by reason of the engagement of Athe bifurcation 49 under the head 46of said valve member 43. The valve member 43 will be held in itsposition, permitting the escape of vsteam from within the cooker. Asindicated above, the provision of the ball valve 60 will prevent theapplication of excessive pressures to' the whistle 63 and will limitsaid pressures to those which will produce` the desired tone in saidwhistle 53. Whenv the steam' has escaped from the cooker, the cover I'Imay be readily removed by backing o ff thetension on the spring 2|),vlowering the cover slightly and swinging it to allow passage of saidcover through the elliptical opening in the vessel I0. A

By reason of the fact that the Weight 54 is pressure for the desiredperiod of time, the steam may` be positively and completely released, tothe end that the cover maybe readily removed from steam will escapethrough the whistle 63, giving 'l a warning to the operator.

valve 60 will be raised, thereby limiting the pressure upon the Whistle63'and maintaining the pressure upon saidwhistle 53 at such a value thatit will operate elciently.

According-to practice which is at. present pre- In the event of excesssteam pressure within the vessel I0, the ball.

the vessel.

'I'he provision of the ball valve 60 has the advantage that the whistle53 may be small enough to operate on low pressures but will be protectedIt need not be exagainst excessive pressures. plained that the ordinarywhistle will not operate properly at both low and high pressures. Theball valve SII has the function of maintaining a predetermined pressureon the whistle, as well asvto expedite the release of pressure withinthe cooker when the operator desires to open the cooker.

The operator ofthe cooker, either by reading instructions or byexperience, will know that when she sets the weight 54 at any one of theindicia on the leg 48a, the valve member 43 should lift in a certainnumber of minutes r'to produce'the desired results. If the thermometer54 indicates that the temperature (and consewill adjust the source ofheat accordingly to effect the accomplishment of the desired pressure(and temperature) at the end of the proper length of time. Moreover, itis frequently desirable to hold a pressure within the cooker for apredetermined length of time after said pressure has been attained.'I'he operator mayturn the weight out toward the outer end of the'leg48a, and, observing the thermometer 64, she may adjust the source ofheat to maintain said pres- Sure.v

f Though a preferred embodiment of thepresferred, the operator, when thefirst warning has The spring 52 has l ent invention has been describedin detail, many modifications will occur to those skilled in the It isintended to cover all such modications that fall within the scope of theappended claims.

What is claimed is:

1. A valve including, in combination, a housing having a valve seat anda reciprocable valve member biased to closing position upon said seat, aJ -shaped lever hingedly supported by said housing, one leg of saidJ-shaped lever being provided with bifurcations, said valve memberhaving' a head-portion adapted to be lifted by one of said bifurcations,said head portion being adapted to engage the other of said bifurcationsto swing said lever as the valve opens, said other leg of said leverbeing provided with a weight adjustably mounted thereupon for varyingthe valve closing force of said lever, said valve being provided withmeans for holding said lever releasably in lifted position.

2. A valve including, in combination, a housing having a valve seat anda reciprocable valve member biased to closing position upon said-seat, aJ-shaped lever hingedly supported b y said housing, one leg of saidJ-shaped lever being provided with bifurcations, said valve memberhaving a head portion adapted to be lifted by one of said bifurcations,said headportion being adapted to engage the other of said bifurcationsto swing said lever as the valve opens, said other leg of said leverbeingprovided with a weight adjustably mounted thereupon for varying thevalve closing force of said lever, said valve being provided with meansfor holding said lever releasably in lifted position, a pin forproviding a hinged connection between said housing and said lever, saidpin having a linger grip portion and a' threaded portion adjacent tosaid finger grip l ently of movement of said iirst mentioned valvemember and being located in a position to bypass said whistle whereby tolimit the pressure applied to said whistle to the end that said whistlemay be small enough to operate on low pressures but will be protectedagainst excess pres- SureS.

ERIK G. GRUNDSTROM.

